The present invention relates to a machine and a method for packaging poultry products, particularly Cornish hens, and for breaking the hocks of the poultry products during the packaging operation.
Machines for automatically packaging poultry products in individual bags are well known in the art. U.S. Pat. Nos. 4,221,106 and 4,270,336, both to Altenpohl et al, illustrate such a machine. In the Altenpohl et al. machines, double leg suspended poultry products are dropped from a moving conveyor and guided into bags by a nozzle assembly which effects limited expansion of each bag in advance of the entry of each poultry product into the bag. A ram is provided to pack each poultry product fully into the bag after partial entry of the poultry product, resulting in tight fit packaging upon withdrawal of the ram and the nozzle assembly from the bag as it is detached and dropped onto a receiving surface.
One of the problems associated with packaging poultry products is the need to compress or compact the product so that it can be readily placed into a bag for further packaging. To this end, the hocks on the poultry product are broken to compress the legs against the body. A variety of different approaches have been used to solve this problem. U.S. Pat. No. 4,458,380 to Tendick et al. for example illustrates a machine wherein a cam actuated tray picks up the bird while it is hanging from shackles, and pushes the bird towards its legs so that the legs are forcibly flexed. U.S. Pat. No. 4,141,194 to Rochman illustrates a chicken packaging machine having tong-like gripper means for engaging the legs of a chicken as it comes from a conveyor and a hopper into which the gripper means forces the chicken. In the hopper, there is a bottom plate against which the chicken rests. While in this resting position, the chicken's thighs are pressed against its body by movement of a set of sleeves to which the gripper means are attached. After the chicken's thighs have been pressed against its body, the bottom plate is withdrawn and the compacted chicken is allowed to drop into a bag for further processing.
U.S. Pat. Nos. 4,219,989 and 4,432,188, both to Andrews, relate to a method of and apparatus for stretch bagging a poultry carcass. As described in these patents, a plurality of open-ended stretch bags are supported in superposed array. Pressurized air is forced into the top of the open-ended stretch bag so as to open the bag. Thereafter, the bag is stuffed with an inverted fowl carcass such that the breast plate is uppermost and the legs protrude rearwardly. As shown in FIG. 8 of each patent, the chicken's hocks are broken manually to compress or compact the bird within the package.
U.S. Pat. No. 4,352,263 to Andrews relates to an alternative method for stuffing a chicken carcass into a stretch plastic bag. The method is characterized by the alternate application of a central pushing force and a chicken leg pushing force, so as to hock or compress the chicken within the stretch bag.
Despite the existence of this packaging machinery for poultry products, there still remains a need for a machine that automatically breaks the hocks of the poultry product while facilitating the packaging thereof. There also remains a need for a machine that is not limited to the use of stretch bags.